Lithium Battery Structure

Lithium batteries usually have two appearances: cylindrical and square. The battery uses a spiral winding structure inside, with a very fine and highly permeable polyethylene film isolation material between the positive and negative electrodes. The positive electrode includes a current collector composed of lithium cobalt oxide (or lithium nickel cobalt manganese oxide, lithium manganese oxide, lithium iron phosphate, etc.) and aluminum foil. The negative electrode is composed of a current collector composed of graphitized carbon material and copper foil. The battery is filled with an organic electrolyte solution. In addition, a safety valve and a PTC element (partially used in cylindrical types) are also installed to protect the battery from damage when the battery is in an abnormal state and the output is short-circuited.
The voltage of a single lithium battery is 3.7V (3.2V for the positive electrode of lithium iron phosphate), and the battery capacity cannot be infinite. Therefore, single lithium batteries are often connected in series and parallel to meet the requirements of different occasions.